Refining process and apparatus



Oct. 14, 1952 H. c. REED ETA. E

REFINING PROCESS AND APPARATUS Filed July 2, 1948 /Vil @S Al m\\ Patented Oct. 1.4, 1952 2,614,067 ReelNINGrROCESS @APPARATUS Homer. C. Reed; Glendale, Clyde H. 0. Berg andi Charles B..I1effert,z-,Lollg Beach, Calif., assignors.

to .-Unionv Oil Company of California, LosAnf geles, Calif., a; corporation. of .California poliertem-Juelz, 194s,- serial Naea'zar.

This invention relatesto a process.andiappar-A ratus-ior the refining of heavy-'oilsisuch as crudes petroleum, straight'v runand crackedf residuums, cokerf distillates; mineral oils such as. those recovxered from shale', tarv sand; diatomite,1and: miscellaneous bituminous sands: which :may 4or may. notf hel contaminated'- with undesirableV elements suchl .as nitrogen,v oxygen an'd sulfur-containing hydrocarbon compounds, coal" oil? fractionspanticularlythose of high density recovered. from.'

the 'distillate produced during coal coking` which may be contaminated withy acidaorfloasicallyzreacting constituents, for the" production of.- lighter' productsYY such as liquids 4boilingv lcelovvk about 800 FI, fractionslof which' are lsuitablelfor-fuels :ininternal'A combustion enginesuand diesel engines,

lubricating. oils, solvents; miscellaneous naphthaa and the like.

More` particularly thislinvention relates to rening processes for the conversion orv highf densityror low A. Pf. I; gravitywoils to products; ofA lower boiling range and lower densityyvhich in'- volve coking` these oil's'toy form' coke andl a1 vCoker4 distillate 'andi hydro'genating the distillate in the presence of Water; and arnetalfcapablerof'eree acting-:with waterto form hydrogen. l

Thehydrogenation.Lofmincralfoils'i and the like; isvvvell known inthefart;A Generallytlfiisv has been'l accomplished by `subjecting the vloilzto be' hydro.-y

genated to temperatures ofv fromf200`-Eftoaabout- 600 E. and from aboutil atmosphere to as high/as; about 100 atmospheres ofhydrogen"in.the pres Another objectof this inventionfis toilprovidev al process Vfor converting khigh densityL oils" which" m'aybe' contaminated withA undesirable' constitu'- ents tof'de'sirable'products oflower "boiling rangeand density 'includingA the steps' of cc'kinggthehigh' density oil"y in the presencerof spent solids' fro'mithe hydrogenation operation, 'simultaneouslylregeneratingfthe spentiY solids andconverting the coketo *producer g'as and employingthe` re` "se claims. (el. 19e- 49) 2v generated.l solids*l in thegproduction of! hydrogenand the:.simultaneousirhydrogenation ofthe heavyr oil. e f z Another object of this inventiorris: to providel an. improved process for`r theyrecoveryfoiggele mental sulfur: vfrom sulfur.: contaminatedv. crude.-

petroleum; y I .5;

A- further object of. thiszinventionzs' tdprovide: an. improved process for-v the; reduction :ofi oxides ofV metals'v suchfas ironfto'.ilovveroxidationStates or toitheirA elemental form; which;involveswsteps;A of laying; down a layer ofrcoke. on theoxidegparfticle and; reacting` the coke-laden. oxide; ati-581er vatedtemperatures;` in' azfluidized vessel, to.. pro-- duceproducer gas andythe .metal-.in vaiinely, di videdstate.` y .i2 1r :1.1-

Another objectof this invention istof provider an improvedv methodffor :the 1hydrogenatiorly; ofl heavy oils. which comprises reactingz.a;-f.fne1y dieevided metal or oxide vof-a l,metal abovefhydrogen: in the: electromotive seriesof -metalsqwtmwater' in the presence of theoil to .befhydrogenatedetov form the metalcxide;,recoveringthezmetaloxide: from Vthe hydrogenatedfmaterial, layingdowrr a layer of. coke onl the :oxide i particlesfand convert= ing, the coke-.bearing oxidet-to the elemental metal., ory to la. lower oxide. forgreuselas; anhdrogenation. catalyst and `as a .source of hydrogen; A further object-of this,invention.istoprcyide an improved continuous'process fori; the hydro-2 genation of: oilsrwith hydrogenzprcduced byf'the'i reaction of elementaliron withwaterr'or Vapor- It'is also an objectv of" the present invention. to' `provide -anfapparatus byfwhich the a-forcmen`` tioned processes may beeiected.

v Other volojects and'advantages of this i'nventi'on' will become. 'apparent' to those skilled' ink the; art. as thedescription'thereofproceeds....i 1..

einem; the preferred' modinction of, tmsln';u ventioncomprises .the high .temperature pyrl" A-.I- sis of'hydrocarbonvoils in the-presence :ofrfparltrf cles; of. ai. spentmetal .oxidefinla,iluidizedycokn; zonewhereby a layer-orcoke is. laidfsdownfsonethe: particles `:and lower: boiling;v hydrolcarbon'pyrolysiss productsvare. formed, separating;V thez'cokel-gladen; oxide .particles from; the; pyrolysis fproductsgl reef actingrithe coke with the spenti" oxide fp'arti'cles i'n1 a. uidizedff reducing regenerating zone tof form* regenerated particles; fcombiningf-a-p'ortion of'the'- regenerated particles 'withl a-tfleasta-'partf ofi tlie pyrolysis'; product;v subjecting :the'mixture-thusf formed to" conditions off 'superatmospheric tem-:1 peratureand pressure in theI-preserce'fofwaterf thereby hydrogenating the pyrolysis product and forming a spent metal oxide, separating desirable fractions of the hydrogenated product thus formed, recovering the spent oxide and recycling it with the high density oil to be coked.

The process of the present invention eliminates virtual1y1all of the aforementioned disadvantages and employs an inexpensive rugged catalyst. The process further utilizes hydrogen generated under superatmospheric pressure in the presence of the oil to be hydrogenated thereby eliminating the compression facilities usually required for high pressure hydrogenations. The hydrogen is generated from water and a metal or a metal compound which also acts as a catalyst. The solids employed are readily recoverable if desired, and such small losses as do occur are not important since the material is readily and inexpensively obtained.

In the process of this invention, the solids employed preferably comprise a finely divided metal above hydrogen in the electromotive series of metals, which may or may not contain a minor quantity of oxides or suldes of that metall and which is also capable of reacting with water for the liberation of hydrogen. Such metals as iron, zinc, cobalt, nickel, and the like, may be employed, those of atomic number from to 30 being suitable with exception of copper as well as the lower oxides of these metals. In the preferred modification of the process, nely divided iron of the type generally known as sponge iron, is preferred. These materials are rugged, easily recovered, highly reactive under the conditions of the process, and relatively inexpensive. The iron particles may be prepared in a variety of manners, although the preferred method involves the reduction of nely divided iron oxides known as mill scale obtainable from such sources as rolling mills and the like. The solid particles may also be prepared by the reduction of finely ground and naturally-occurring iron oxides or from other sources.

In the coker, reducing regenerator, and the oxidizing regenerator, fluidized suspensions of solids are established in gaseous mixtures in a condition of hindered settling. The gases move upwardly while the solids slowly settle and a thorough countercurrent contact is effected as well as precise temperature control. The iron serves to decompose Water to produce the required hydrogen and also perform as a mild` hydrogenation catalyst.

During the hydrogenation step of the combination process of this invention, the sponge iron catalyst is commingled with the oil to be hydrogenated and a predetermined quantity of water to form a slurry. This slurry is introduced at high pressures through a heater into an agitated hydrogenation vessel. A completely liquid phase reaction occurs at temperatures sufficiently high to effect the reaction of water and elemental iron and which may be as high as to cause further decomposition of the hydrocarbon to be hydrogenated. By carefully controlling the temperature of the hydrogenation, a variable degree of destructive hydrogenation or combined hydrogenation and cracking may be effected in the presence of iron which may also act as a hydrogenation catalyst as well as the source of hydrogen. During this hydrogenation reaction, the iron is converted to iron oxide. Hydrogenated oil, iron oxide, and unreacted water etc. are introduced into a suitable separating device for recovery of the individual fractions of the mixture. Such a separation may be effected in a conventional fractionating column of the bubble tray type in which hydrocarbon fractions of any desired boiling range may be recovered along with the iron oxide and any residual oil. In such a system, the residual oil contains iron oxideformed in the hydrogenation vessel and this residual fraction is preferably combined with the high density oil to be treated and reprocessed.

Occurring simultaneously with the hydrocarbon'hydrogenation step is an eicient desulfurization by means of which sulfur compounds are decomposed with the ultimate formation of iron suldes which are removed with the iron oxides in the residual oil from the hydrogenation product fractionator. The process provides means for separation of iron suldes from the iron oxides and the oxidation of such sulfides to form sulfur dioxide. The sulfur dioxide is subsequently converted to elemental sulfur by effecting a reaction of sulfur dioxide with carbon monoxide contained in producer gas. The sulfur may be recovered either as a finely divided solid or as a liquid depending on the temperature. If desirable, this sulfur dioxide may be further oxidized and converted to sulfuric acid.

The nitrogen compounds which may be present in certain types of high density oils to be treated are decomposed under conditions of hydrogenation with the formation of ammonia. Since the hydrogenation is accomplished in the presence of water, the fractionator may be operated under such conditions so that the overhead temperature permits the removal of an aqueous phase containing dissolved ammonia from the upper portion of the column.

The process and apparatus of the present invention may be more clearly understood by reference to the drawing in which a schematic flow diagram of this invention is shown. To further facilitate the description and to also provide a practical operating example of the process, the following description of the drawing will be conducted in the form of an example in which high density crude petroleum produced from the oil fields of Santa Maria Valley (California) is the oil to be treated and in which the catalyst employed is sponge iron. Flow quantities are given and operable ranges of pressure and temperature as well as preferred operating pressures and temperatures are included.

Heavy oil colczng Referring now more particularly to the drawing. 260 barrels per day (42 U. S. gallons per barrel) of Santa Maria (California) crude petroleum amounting to 43.9 tons per day is treated according to the process of this invention. This heavy oil is preferably topped for straight-run gasoline recovery. The crude petroleum passes via line I0 under pressure exerted by pump II through line I2 controlled by valve I3 and is combined with 49 barrels per day of coker residuum recycled through line I4 controlled by valve I5 and with a stream containing 8 tons per day of hydrogenated residuum, 2.76 tons per day of iron sulfide. and 20.9 tons per day of ferrie oxide flowing through line I6 controlled by valve I 1. 'I'he combined stream is introduced via line I8 into heater I8a wherein it is heated to a temperature of from about 700 F. to as high as about 1200 F. and preferably to about 900 F. The heatedA stream then passes via `line I9 into coker 2U 'wherein pyrolysisfof .the hydrocarbons is eie'cted with they formation. of hydrocarbon pyrolysis products of lower boiling range and a mixture of iron oxide and iron sulnde particles laden with coke.

Coker 2U is a vessel in which the particles of iron compounds such as higher oxides FesO4 and FezO3 are maintained in a fluidized state due to the mixing action of hydrocarbon liquid and vapor being'intro'duced from heater I8a. The cokeladenv iron compound particles Vare present -in vessel 20 in a state of Ahindered-settling land act muchas a high density'fluid 'which accumulates iny a lower-portion of the yvessel. Thus 'a levell 2l exists below which the fcoke-laden-particles 'are inrapid-motion, hinderedfromsettlingrandlabove which the particles tend tosettle forming asolidfree-gas space. Present within-eckerZuisseparator 22fby meansof which lparticlesof suspended ironcompoundare'removedffrom the hydrocarbon pyrolysis product yand returned to thelower portion'of the vessel` vCokerv2llpreferably is operated atsuperatmosph'eric -pressure irom'about zero to ashig'h-asZOO pounds' per square inch gauge, `and preferablybetween about and 100 pounds per square inch. 'Coke-laden particles of iron oxide and iron sulfide are removed from coker 20 by means'of line -23'controlled by'valve 24 and are sent thereby to reducer V25.

The hydrocarbon 'pyrolysis' products, as la -vapor phase, pass'rom separator22l by'means of line 26 through Vcooler 27 Aand'fsubsequently via line 28 into .lcokerbubble tower 2S wherein they are fractionated. Other forms of distillation column suchfas-a'p'acked tower may be'used'as well. The overhead product passes` by means of'1ine3ii into cooler 3l wherein 'a partial condensation of the coker 2D is effected. Thecoke is burned in thel lower boiling hydrocarbonsis efected. The combined liquidand gas'pass vialine 32A into separator 33 wherefrom vthe liquid'products are withdrawn via line 34. A portion of thispasses by means of'line 35i-controlled by valve 36 into the upper portion of fractionator 29 asreux'while the remaining portion passesvia line 3'!v controlled by'valve 38 to further `processing facilities or storage facilities :not shown. This` hydrocarbon stream comprisesfalcoker gasoline which, depending upon the operation of coker bubble tower 29, may have an end point of from as low as about 150 Ftto as highas 400 F, In this operation 23.6barrels per day, or 2.65 v tons per dayf'of la- 250 F. end point gasoline are'produced.

The ga's phase present inseparator 33 is removed .therefrom vialine .39 controlled by valve 40 and is introducedinto absorber 4l in which the removal of normally liquid hydrocarbon fractions from .the'gasis effected. To effect this removal, a gas oil .fraction is removed from bubble tower 29'by means of line 42, passed through cooler -43 andintroduced into absorber'll by means of line 44A controlled by valve 45. This hydrocarbon fraction, a Coker gas oil, passes downwardly throughabsorber 4lA Vcountercurrent to the upwardly rising gases and a dry gas consisting substantially of. hydrogen, methane, ethylene, ethane, and the like.is removedA by means of vline 46 controlledby Valve 41. v

The rich aborption oil produced in absorber 4 isremoved therefrom by means of line 48 a portion of which `is returned via line @controlled by valve 5B to cokerbubble'tower '29 while the remaining yportion passes,` by meansof Yline 50a controlled'byvalve SII-.tube hydrogenated asfherenafter-described. The-*quantity ofcoker distillate 5 and 5.0.

thus produced for hydrogenation: amounts :taf-2&2

laden iron oxides and iron suliides which are formed in coker 20, these solidparticles arelcol.-

lected in one portion of coker 2U from which they` are removed by means of line 23 controlled by valve 24 at a rate of 31.4 tons perday and introduced into reducer 25. Thisl solid material ana-l lyaes, inper cent by weight. asfollows:

Constituent: WeightperY cent` Iron sulflde. .rr l8.8. Higher iron oxides .66.4 Coke ,22.0 Chloride 1-l rl .1.9 Sulfur f0.9

'I'otal 100.0

This material passes into thereducer at.. about 900 F.

The operation of the reducer is such that an effective carbon or coke burn-ofi from the solid particles upon which the coke was laid down in presence of an oxygen-containing gas such .as air to produce mainly carbon monoxide. This coke burn-off is carried `off at temperatures between about 1400" 1T'. and 1800 F. or higher. A suitable temperature for this reaction is about 1650c F. Simultaneously with the coke burn-off, the coke present on the ironoxide particles effects a substantially complete reduction of this iron oxide to an iron compound of a lower oxidation state capable of reacting with water to liberate hydrogen such as particles of ferrous oxide (FeG) or particles of elemental iron in finely divided form. To eiect this operation 1.95

ii/iSCF/Hr. (1,000 standard cubic feet'per hour) of absorber dry gas or other hydrocarbon gas such as natural gas, which may be preheated to a temperature of about 1200D F., is introducedl into reducer 25 via line 52 controlled by valve 53. At these temperatures, a. hydrocarbon-iron oxide reaction occurs which gives rise to the formation of carbon monoxide, hydrogen, water and elemental iron. To effect the coke burn-off, 3.81 MSCF/I-Ir. of air as the oxygen-containing gas, which also may be preheated to a .temperature of about 1200 F., is introduced into the lower duce high purity ironA from the reducer, itis pref'-A erable to maintain a carbon'monoxide tocarbon dioxide ratio (volume) of greater than about 1.0 in the producer gas such as between about 2.5 A ratio of about 3.0 is preferred to insure reduction of the oxides to elemental iron. For reduction to errous oxide (Feo), a ratio of from about 0.5 toas high as about 3.0 may be used. This gas is introduced into separator v5l in which traces of suspended particles v*are removed Iand 'returned tothe vhigh A"density'sus- 7 pension phase below level 56. From the upper portion of separator 51, 5.39 MSCF/Hr. of a producer gas analyzing about 80% carbon monoxide is removed at a temperature of about 1650 F. via line 58. This producer gas passes subsequently through heat exchange means 59 whereby it is cooled considerably losing its heat, in one modification of this invention, in indirect heat exchange with the hydrocarbon gas and air introduced, as previously described, into reducer 25. The producer gas is thus cooled to a temperature below 1,000 F. and is passed by means of line G into separator 6| wherein remaining traces of suspended solid particles are removed. These particles may be recovered from the producer gas in a high voltage electrical precipitator or in especially designed centrifugal type separator such as a cyclone. Recovered particles may be returned to reducer 2 5 via line G2. The solids-free producer gas is removed from separator 6| by means of line 03 and a portion of this is sent via line 64 controlled by valve 55 for use as fuel, such as in furnace i3d in which the incoming heavy oil feed, recycle Coker residuum,

and hydrogenated residuum are raised to colring .f-

temperatures prior to their introduction into coker 20. The remainder of the carbon monoxide gases pass via line G6 for further processing in connection with the recovery of elemental sulfur from the sulfur dioxide bearing gases produced during the conversion of iron sulde to iron oxide, as hereinafter more fully described. The reduced solids are removed from reducer via line I I 2 and a portion may be passed through line I |2a controlled by valve I I3a directly into the Coker in which part of the desulfurization may be eiected at coking temperatures.

Metal sulyide oxidation In oxidizer El. '7.73 tons per day of solid material containing 91% iron suliide, magnetically separated from the reducing regenerator eiiiuent, as hereinafter described, are introduced and converted to higher iron oxides. This reaction is conducted at a temperature of about 1200o F. although temperatures as low as about 1,000 F. to as high as about 2,000 F. or higher may be employed, if desired. The iron sulfide is sus pended in an air stream introduced by means of line GS controlled by valve 69 and the suspension together with recirculated iron oxide is passed via line 10 through waste heat boiler 'II wherein a portion of the heat generated during oxidation of the iron sulfide is dissipated in converting water introduced via line 8| controlled by valve 82 into steam which is removed from separator 83 via line 84 controlled by Valve 85. The suspension is then passed from boiler 'll via line 'I2 into oxidizer 67. A level 13 is maintained in oxidizer 61 below which iron sulfide and iron oxide particles are maintained in a condition of hindered settling as a relatively high density suspension. The solid particles are removed from oxidizer El via line "I4 controlled by valve 'I5 and a portion thereof is returned via line I6 controlled by valve 'l'l' to be recombined with the incoming iron sulde and air for recirculation through Waste heat boiler 'EL The quantity of this recycle stream amounts to about 108 tons per day, although higher or lower recycle rates may be employed in order to maintain the oxidizer temperature at the desired value. The remaining quantity of oxidized material passes Via line I8 controlledby valve 'I9 into auxiliary 8 reducer at the rate of 7.1 tons per day and has approximately the following composition:

Constituent: Weight per cent FezOs 83.0 F8304 9.1 Fes 7.9

Within auxiliary reducer 80 this downwardly fiowing solid mixture contacts a countercurrent stream of gas removed from reducer 25 at a rate of 1.4 MSCF/Hr. by means of line 86 controlled by valve 81 and which contains carbon monoxide. This countercurrent contact effects a substantially complete reduction of the FezOa to F8304. and simultaneously the solids are heated to approximately the temperature existing within the reducer, that is, about 1650 F. The Fe04 thus produced, containing about 8.0% iron sulde and substantially no FezOa, is passed from auxiliary reducer 80 by means of line 88 controlled by valve 89 into reducer 25. The gas removed from auxiliary reducer 80 after contacting the oxidized iron sulfide from oxidizer 61 passes via line 90 controlled by valve 9| into oxidizer 6l.

Within oxidizer 61 the iron sulfide is oxidized to a mixture of iron oxides with the simultaneous production of gases rich in sulfur dioxide. Under conditions of the present operation these gases are removed from oxidizer 61 through separator 92 by means of which suspended particles of iron oxides are separated and returned to a point below level '13. The solids-free sulfur dioxide bearing gases are removed from separator 92 by means of line y93 controlled by valve 9d and are introduced into separator 95 which preferably is of the high voltage type, by means of which remaining traces of very fine solids are precipitated. The solids thus recovered may be disposed of or returned to the system by means of line 96. The sulfur dioxide bearing gases, free from suspended particles, pass from separator 95 by means of line 91 at a rate of 22.0 MSCF/Hr. and are combined with 14.3 MSCF/Hr. of producer gas containing a high concentration of carbon monoxide owing through line 68.

Sulfur production The gaseous mixture thus formed has a temperature of about 1100 F. and contains carbon monoxide and sulfur dioxide under conditions at which they readily react to produce elemental sulfur according to the following reaction:

This gaseous mixture is conducted by means of line S8 into waste heat boiler 99 wherein the heat generated is employed to convert water to steam. Water is introduced by means of line |00 controlled by valve IUI and steam formed is removed from separator |02 by means of line |03 controlled by valve |04. The heat made available by this reaction is about 300,000 B. t. u. per hour, a substantial portion of which is recoverable in the form of high pressure steam. Gases are removed from boiler 99 at a temperature of about 1185 F. by means of line |05 and are introduced into heat exchange means |06 wherein the gases are preferably cooled to a temperature of below about 250 F. losing their heat in this modification at a rate of about 500,000 B. t. u. per hou'r in the generation of steam. Sulfur is hereby precipitated in solid form and liquid sulfur may be recovered, it

desired. by ,maintaining thetemperature fabove 250 vRsuch as for example,at least 300 F. This gas is introduced vvia line |01 into separator |08 wherein the `sulfur is separated. Sulfur is thus produced at a 4rate of about 1.8 tons per day and is `removed from separator |08 via line |09. The sulfur thus Vproduced is of high purity. T Ihe solid sulfur is in a finely divided form suitable -for a wide variety of uses, especially fruit tree dusting.

The reaction of carbon monoxide and sulfur dioxide does not go to completion so that the gases removed from separator |08 by means of line I| are contaminated with -unreacted quantities of 4sulfur dioxide and small quantities of hydrogen sulnde formed through the reaction of sulfur dioxide with water vapor. In order t0 recover these quantities of sulfur, the eas removed irom separator |08 via `line H0 controlled by valve is employed at a rate of about n34.2 MSCF/Hr. to convey and simultaneously to cool the iron eiiluent removed Vfrom rei ducer 25 at a `rate of 26.2 tons per day by means of line ||2 controlled by valve ||3. These `solids are removed from reducer 25 at a temperature of about 1650 F. and have kapproximately `the following weight composition:

Weight per cent Constituent Iron 4.95 Iron oxide (FeO) 17.0 I ron oxide (Fe304) 9.9 Iron suliide A 21.3 Chloride 2.3

In doing this an ecient contact of the residual sulfur-bearing gases with iron is effected substantially completely converting the sulfur to nonvolatile metal compounds such as iron sulde. The metal sulfur compounds are recirculated through the system for reprocessing and permit the discharge to the atmosphere of gases substantially uncontaminated with sulfur and a substantially complete sulfur recovery. The gaseous suspension thus formed passes by means of line Hd into separator ||5 wherein the solids. comprising a mixture of iron oxide and iron sulf-fur; compounds together with iron, are separated. from the heated gases. The solids thus conveyed and cooled are removed from separator l|5 at a rate of about 26.7 tons per day at a temperature. ofl about 825 F. These solids have approximately` the following composition:

Gases alle. removed from separator H5; at a temperature of 825 F. via line I l0 having a sub.Y stantially reduced sulfur content.

The solid material containing recovered iron sulfur compounds removed from separator U5.

passes via line |20 and may be quenched by di-v rect contact with about 8O tonsY per day of water introduced by means of line |8 controlled by valve H0, about, 15.0? and 190,000.15. t. u. per hour of .heat

a1;e,recov ered. The .slurry of; solidsin waterpass. vialine v |20, into primary magnetic. separator. |211.

The temperature is thus reduced to.

10 .wherein -a substantially complete separation of iron suldes V-is efiected; .'lhef elemental iron fand iron oxides thus recovered is removedfrom'separator .|21 Avia line |22 `controlled by valve vZil-at a rate of 25.1 tons per day. Thestreamhasfa'p'- proximately the :following composition:

Constituent:

This .slurry of .iron and water is lcorrifbinedwith' 212 barrelsper dayof. Coker distillatuiemoife from the lower outlet of absorber 4| and flowing through lines "48 and 50a controlled 'byfvalve'i?.v This material is subsequently passed-Aby Lmeans of line v|24 .to the hydrogenationstep of tlfitfioroc- A ess which will subsequently be described Also removed from vmagnetic separato U02| is a stream of the relativelynonmagnetic'materials containing ,substantially all of the -si'lde.' and some iron oxide, the chlorides, and the like.

This material is removed by means of line? |25V y controlled by valve |26 and is introducedginto secondary magnetic separator |21 whereina-,sepa?I ration of the ash and chlorides is eiected from the iron oxides and ironsuliides. The 'ash-gand chlorides and other nonmagnetic materials are removed by means of line |28 controlled by'vvjalve |29 and are discarded The iron 'sulfide contiene -r trate is removed by means of line |=30 control-led by valve |3| at a rate of about 10.2 tonsjfpor dayA and has approximately the following compositio Constituent: .per .cenitl Fes 69.4

1601i This material passes by means ofV 1inev|32fandA is combinedfwit'ha large volume ofy gasesremove'd' from separator H5 vialine-Hiy at atemperature o about 825 rhis gasy is again employed-to convey solidV materials and simultaneously "tonite-fl move last. traces of sulfur compounds. Watercis evaporated to,- torma completely gaseoussuspee sion of. iron sulfide and-a small` quantity-of'` iron' oxide (FesOilandi thesuspension ispassedfby means. ofi line |33 into separator |34` at a" ten peratureJ of about/425 Fa Withinfseparatorf 34;? suspended. particles ofi- FeS# andjFegO4A are rel,`` moved fron-litho suspendedfgas These'arefpasse'd by means. ofline |35 controlled by valveT `|3|; ati a rate of. '7.7. tonsY per` da-ytofbecdmbinedfwitii air for. introduction intolox-idizer '6 .l Thesulfur'ef free` gases are. discharged to the""atmospliere y` means of line |37 at a rate-of? aboutrSlifMSCF" 1211*?` AV substantially complete sulfur-'recoveryf'as efementaly sulfur may befeffectedfinthis mannen? f .arate of 59.6

-of various types which enhance the hydrogenation reaction orv these hydrogenation accelerators may be added, if desired, directly to the hydrogenation reactor. Hydrogenation accelerators applicable in this respect are the water-soluble halides of metals such as calcium, magnesium, iron, manganese, and the like, as well as the halides of ammonia.

The slurry prepared in mixer |38 passes by means of line |44 into high pressure pump |42 by means of which the slurry is compressed to a pressure which approximates that reouired in the nultimate hydrogenation reaction. This slurry is passed under high pressure through line |43 at tons per day controlled by valve l|44 into heater |45. Material introduced into heater |45 has the following weight composition:

Constituent: Weight per cent Fe 20.1

i FeO 7.5 F6304 3.3

1 Chloride 1.0 {Q Water 13.8 i Coker distillate c 54.3

In other operations, the composition may be vai-led to obtain different degrees of hydrogenation. From 5% to 35% iron, or ferrous oxide, 2% to 25% water, and 30% to 90% oil may be employedyfor example. l This material is removed from heater |45 by means of line |46 controlled by valve |41 and is introduced at a temperature between about 500 F. and 1200 F. into hydrogenation reactor |48. In!l this particular operation a temperature of about 750 F. was employed in the hydrogenation of. the coker distillate. Hydrogenation reactor |48 is provided with agitator |49 and driving means |50 whereby the contents of the reactor are maintained in a. condition of thorough agitation during the entire reaction.

-lit is sometimes desirable, where heating of the comblnedhydrogenation reactor feed is not feasible, to separately heat the oil containing the suspended iron in one stream and the water which may contain a dissolved hydrogen generation accelerator in the other. In this modification, the magnetic separation is effected in the absence of water. The water is then introduced at high pressure via line |49a through a separate coil in'heater |45 at a rate controlled by valve |50rt directly into reactor |48. The temperature may be above or below that of the inlet oil stream and may in some instances be at pressure and temperature conditions above the critical. Such an operation permits the complete iron-steam reaction for hydrogen production to-take place under the conditions best suited for hydrogenation.l A very effective utilization of the hydrogen thus formed is effected.

'I'he pressure under which the hydrogenation reaction is accomplished is above atmospheric ranging as high as 15,000 pounds per square inch (1,000 atmospheres). Lower pressures may be employed such as less than about 100 pounds per square inch, although in the hydrogenation of such material as coker distillate obtained from Santa Maria Valley crude petroleum, pressures in the range of from 3000 to 9000 pounds per square inch are desirable.

During its passage through hydrogenation reactor |48 the mixture of iron, water and coker distillate reacts for the conversion of the 11nsaturated hydrocarbon constituents of the coker distillate to saturated or parainic fractions, the destructive hydrogenation of the higher molecular weight and higher boiling hydrocarbon constituents for the production of saturated hydrocarbons boiling in the lower temperature ranges, the destruction of nitrogen, oxygen and sulfurcontaining hydrocarbon compounds with the formation of ammonia, water, and hydrogen sulfide, respectively, and substantially completely hydrogenated remnants of these constituents, the conversion of the iron and FeO through reaction with water to higher oxides of iron such as Fe3O4 with the simultaneous production of hydrogen which is employed substantially as it is formed in the aforementioned hydrogenation reactions, and the conversion of a portion of the iron or iron oxides to sulfides of iron through reaction with hydrogen sulfide or with the sulfur-containing hydrocarbon compounds.

The heterogeneous mixture of solids and liquids containing dissolved gases is removed from hydrogenation reactor 48 by means of line |5| controlled by valve |52. A portion of the hydrogenation reactor effluent thus removed may be recycled through heater |45 via line |5|a controlled by valve |52a by circulation pump |53a. In this manner the entire system, heater and reactor, may operate under substantially isothermal conditions so that hydrogen generated by reacting iron with water is formed at the hydrogenation temperature permitting a substantially complete utilization as formed. Such a mixing of a portion of the hydrogenated effluent r with the feed to the reactor permits quick heating and avoids the condition encountered wherebythe hydrogen is generated at temperatures during heating which are not sufficiently high to effect the desired degree of hydrogenation.

The remaining portion of the reactor eflluent is'introduced into the central lower portion of hydrogenation eiuent bubble tower |53. In this fractionating column, the hydrogenated eiuent is separated into its constituent parts. An overhead vapor passes by means of line |54 into condenser |55 wherein a partial condensation of the lower boiling constituents is effected. This cooled product passes by means of line |56 into separator |51 from which the gases are removed by means of line |58 controlled by valve |59 which also maintains a back pressure on the column. The gas thus obtained may contain a certain amount of hydrogen as well as the normally gaseous hydrocarbon constituents. This gas may be employed as fuel in the process, or may be sent to storage or further processing facilities not shown. The condensate is removed from separator |51 via line |60 controlled by valve |8| and a portion is returned to the upper part of the bubble tower by means of line |62 as reflux, while the remainder is produced through line |63 at a rate of 55 barrels per day controlled by valve |64. This liquid fraction comprises a hydrodesulfurized gasoline which is substantially free from nitrogen and sulfur contamination. The gasoline may be blended in any desirable proportion with unsaturated hydrocarbon fractions obtained from the coker gasoline product produced from the upper portion of coker bubble tower 290, previously described.

The conditions of temperature and pressure which are employed in the hydrogenation step of the process may be modified by the incorporation of catalytic quantities of such hydrogenation and/or desulfurization catalysts as nickel and cobalt oxides or sulfldes. Molybdenum or tung- 'bons is produced. Condensation of a portion of the vapor removed from the upper portion 'of the column forms a coker gasoline having a boilling range from about '70 F. to as high as about 400 F. The end point of this coker gasoline may be varied by varying the overhead product temperatures of the coker bubble tower. A

coker gas oil may be removed from the coker,

bubble tower at a point intermediate between the pyrolysis product inlet and the overhead vapor outlet. This product contains saturated and unsaturated hydrocarbons boiling in the range of from about 300 F. to as high as about 800 F., the actual boiling range depending upon variable operating conditions of the column. From the bottom of the coker bubblev tower, a coker residuum is removed which may be recirculated and combined with a feed stream and reintroduced into the vcoking vessel for reprocessing. This residuum may also be employed as a raw material for road-building hydrocarbons such as road oil, asphalt, and the like.

If desired, the coker gasoline and coker gas oil may be combined to form a coker distillate which is hydrogenated for the formation of desulfurized and saturated hydrocarbons suitable for internal combustion and engine fuels, lubricating oils and greases. If desired, these streams may also be treated individually by hydrogenation as will be subsequently described, or by other processes.

Returning now to the coking vessel, a stream is removed from below the level maintained in the coking vessel which comprises coke-laden particles of iron oxide (FesO4 predominantly), and iron sulde. This material is suspended in a gas, if desired, or is otherwise directly introduced into a iiuidized reducing regenerator.

The reducing regenerator effects the combustion of carbonaceous materials such as coke present on the iron oxide and iron sulde particles, and also effects a substantially complete reduction of the FeaO:l to finely divided elemental iron or to lower iron oxides such as FeO. The temperature of operation at which the reducing regenerator effects these conversions may be between about 1000 F. and 2000 F., a temperature of about 1650 F. being typical. An oxygen-containing gas such as air is introduced directly into the reducing regenerator in controlled quantities to effect coke combustion which favors the formation of carbon monoxide and liberates heat aiding the iron oxide reduction. Introduced at a separate point in the reducing regenertor is a gas containing hydrocarbons and/or carbon monoxide such as natural gas, producer gas, or mixtures and the like, which assists the reduction of oxides of iron to lower oxides 0r elemental iron. These gases, the oxygen-containing gas, and the producer gas or natural gas are preferably introduced below the level of suspended solids maintained in a uidized state in the reducing regenerator. It is also to be preferred that a portion of these suspended solids be continuously removed, passed through suitable heat exchange means, and reintroduced in a closed cycle to maintain temperature control of the reaction.

In the reducing regenerator conditions are controlled so that the gases produced during the reaction contain hydrogen and water vapor in a ratio of about 2.0 and carbon monoxide and carbon dioxide in a ratio of at least 3.0. Under a pressure of operation which may range from nearv atmospheric to as high as several hundred l been set forth above and are pounds per square inch and under the conditions of temperatures disclosed above the production of a gas containing the constituents recited in the ratios given insure a substantially complete conversion of coke and of the iron oxide introduced into the reducing regenerator to nely divided elemental iron. A stream consisting of iron and iron sulfide essentially, and also containing small quantities of iron oxide is continuously removed from the reducing regenerator and subjected to a magnetic separation wherein the iron and the other materials with high magnetic susceptibility are separated from the iron sulfide. The iron thus recovered is employed in the hydrogenation of the coker distillate.

The iron sulde recovered from the magnetic separator is combined with air and continuously introduced into an oxidizing regenerator in which the oxidation of iron sulfide to iron oxide is conducted under conditions suitable for maintaining the solids in a state of hindered settling and at a temperature of from 1000 F. to as high as 2000 F. In the oxidizing regenerator a suspension of solids is maintained in which a level of iiuidized solids is present. In the upper portion of the oxidizing regenerator the gases produced in the oxidation reaction are passed through a centrifugal separator for the removal of suspended solid particles. Suspended solids-free gases are subsequently removed from the separator containing sulfur dioxide or elemental sulfur depending upon the conditions of operation. Elemental sulfur in liquid or solid form may be produced in the system by operating with a minimum quantity of air required in the iron sulfide oxidation and by controlling the eiuent gas temperature so that at least part of the iron sulfide is converted to iron oxide and sulfur. In this modification the iron oxide formed from the iron sulfide oxidation is continuously removed from the oxidizing regenerator, cooled, and combined with the hydrocarbon feed to be coked and is introduced therewith through the heater into the fluidized coking vessel.

As indicated above, the stream of solids removed from the reducing regenerator is magnetically treated to recover a concentrate of elemental iron. This is mixed to form a slurry with at least part of the hydrocarbons obtained from the ecker bubble tower and with water. The actual quantities of iron and water in relation to the amount of oil to be hydrogenated have dependent upon the quantity of olenic or otherwise unsaturated hydrocarbons which are desirably converted to paraflinic or saturated compounds. Under the conditions of the hydrogenation, iron reacts with water with the formation of iron oxide and the liberation of'hydrogen according to the following reaction.

This reaction supplies hydrogen required in the hydrogenation reaction and is consumed substantially as it is formed. The quantity of iron and water is selected to provide suiiicient hydrogen to effect the desired degree of hydrogenation.

It is desirable to assist the hydrogenation reaction'and the hydrogen generation by the addition to the slurry of halides of ammonia or various metals such as iron, manganese, magnesium. calcium, and the like, which function as accelerators.

The slurry, containing the constituents above described, is pumped through a means for heatacides? ing whereby temperatures from about 50.0 F.. .to about 120.0F. or more are .developed in Ythe sys tem. LThe .heated ,oil is introduced thereby into a hydrogenation reactor at a pressure as .high as about 15,000 pounds per .square inch. This vessel is preferably continuously agitated to permit uniform sus-pension of .the reacting` solids inthe liquid and to assist temperature control. Water, heated and under pressure, may be added .separately from the oil and iron, or the lslurry may be combined with a part ofthe hot reactor eiiluent and introduced into the reactor.

:In the hydrogenation reactor, sulfur-containing hydrocarbon constituents are decomposed presumably by ,destructive hydrogenation with .thefformation of hydrogen .sulde and the hydrocarbon remnant of .the sulfur compound. The hydrogen sulnde ultimately reacts with either the iron .or the iron oxides present iorrn-ingiron sulfide inthe system. Nitrogen-.containing hydrocarbon compounds are similarly decomposed forming ammonia. The hydrogenator .eiiiuent containing the valcove indicated constituents is subsequently passed from the hydrogenation reactor to a means for effecting the separation of the various constituents. in the preferred modification this means for separation may comprise a distillation column from which gaseous hydrocarbons are removed together with hydrogenation hydrocarbon fractions, gas oil fractions and others. Provision is preferably made in the distillation column for the Yremoval of water containing dissolved ammonia which may be substantially completely recovered by this means. From the lowest part of the distillation column a, 'hydrogenated residue .of higher boiling hydrocarbons is removed `'which contains suspended solids including iron oxide, iron sulide, and possibly some unreacted iron. This residuum may be magnetically separated for the recovery of solid particles, or in the preferred modification is combined in its entirety with the heavy oil to be hydrogenated and is returned with that stream to the coking vessel for retreatment. Y u

In accordance with this modification a high density oil is subjected to conditions of thermal pyrolysis and destructive hydrogenation whereby a substantially complete conversion to hydrocarbon fractions to more desirable boiling range is effected. By-products, including ammonia, sulfur dioxide, sulfur, and possibly various suliides and oxides of iron may be produced, if desired. Qne outstanding feature of this process is the fact that a high pressure hydrogenation may be eiected in the complete absence of the extensive gas compression facilities normally required in high pressure hydrogenation operations andalso .in the absence of an expensive and often easily poisoned hydrogenation catalyst. Another advantage of this modication comprises the use of the magnetic separating means for the control of iron sulfide by separating this material continuously and .converting it by oxidation to iron oxide. This eliminates recycling of iron sulde uselessly through the process.

In an additional modification of the process laccording to this invention, a r'luidized coker, a 'fluidized oxidizing regenerator and a uidized reducing regenerator are also employed. In this particular operation the heavy hydrocarbon stream to be treated is combined With a hydro- -genatedresiduum containing iron oxide and iron sulde and with a coker residuum and introduced -via .a nred heater into the coking vessel. The

.oxidizing regenerator is so positioned with respect tothe vecker that iron oxide withdrawn from the oxidizing regenerator ,is combined with the heated hydrocarbon stream from .the heater and thetwo are .introduced simultaneously into the -coking vessel. In this manner .asubstantial utilization .of the-sensible heat `of .iron oxide from 'the oxidizing regenerator .is utilized in causing thermal pyrolysis of the heavy oil being coked. Also in this .manner :iron oxide from the oxidizing regenerator is passed through the coking vesselfand-'a layer of coke yis deposited upon each particle. The .hydrocarbon stream .from the heater :may be at a temperature of between .about I00;.F.;and l200 F. .and usually at a temperature .of about 950D F. and is combined withfiron .oxide from .the oxidizing regenerator at a temperature of about 1.200 F. .prior .to passing into .the coking This .operation may. .be modied somewhat by Yinrtroducing the iron -oxide directly from theloxdiz*y ing regenerator into the coking vessel.

The operation .of the coking vessel isthat of@ iluidized system previously .referred to wherein ya level of suspendedsolids -is maintained. .Inthe upper portion nor the .coking vessel is .situated'a centrifugal separator Where'by'the pyrolysisproducts as vapors maybe removed from 'the .colser While retaining suspended solid particlesdneithc coking vessel. The'pyrolysis product is subsequently introduced into ya distillation column which lmay be ofk the bubble tray type wherein. various vhydrocarbon fractions, gaseous and 1141.-'

uid, are separated from one another. During coking, a certain rquantity of hydrogen sulde is generally formed from the decomposition .of sul.- fur-containing hydrocarbon constituents. material `is removed together .with the hydrogen', C1 and C2 saturated and unsaturated hydrocarbons `from the upper portion of the column. In one .modication of this invention,` the gas 'thus produced is subjected to a treatment .adaptable to removing Athe hydrogen .sulfide thus contained such as by :absorption in basically reacting adsorbents such as aqueous solutions of alkali `.metal salts, absorption in solutions -of organic coinpounds 'such -as ethanolamines, and the like. The hydrogen sulfide-free hydrocarbon gases are introduced into the reducing ,regenerator to eiect the reduction of iron oxide vto finely dividedme tallciron as subsequently described..

The normally liquid portion of the hydrocarbons in the pyrolysis product are further fractionated in the ecker `bubble itower to produce a colier distillate or .coker gasoline boiling'y from about F. tc 400 F.. .anda .coker gas oil boiling from about 350 F. to about 760 F. Thesev stream the total quantity of which istthenhy# drogenated.A .f i

From the lov/est portion lofthe coker bubble tower is removed a coker residuum consisting fof the higher boiling hydrocarbons which maybe employed as iuel oil, road oil, in the preparation of asphaltic road-building material, and'the like. rIhis residuum in the present invention isp'r'efer'- ably combined with the hydrogenated residuum and with the high density oil to be treated and the combined stream is introduced into the coke for pyrolysis. -1

From the lower portion Vof the coking vessel is `removed .a stream of Aiinely divided solids comprising a mixture .of iron oxide, iron suliide `and icone. YIn-this .modification of vthe inventiona minor portion such as from about to 50% by vweight of the stream is suspended in air or other"oxygen-containing gas and introduced at a temperature of about 850 into the oxidizing regenerator. Preferably about one-third of the stream withdrawn from the coker is thus treated. Within the oxidizing regenerator, which may operate from a temperature of about 1000 F. to 2000 F. and preferably at about 1200 F. to 1500 F. the coke is burned to carbonA monoxide and carbon dioxide and the iron sulde is oxidized to form sulfur dioxide and the higher iron oxides. This reaction is conducted in the oxidizing regenerator in the presence of fluidized solids whereby a level is maintained within the vessel. From below this level and from that part occupied by the suspended solids is removed a continuous stream of solids consisting predominantly yof the higher iron oxides at a temperature of about 1700 F. A portion of this is combined with the higher iron oxide, iron sulide and coke removed from the coking vessel and recirculated tothe oxidizing regenerator to eifect temperature control. The remaining quantity is introduced directly into the Coker Where a carbonaceous deposit of coke is laid down on the particlesto permit iron oxide reduction and a portion of which is converted to iron sulde and treated as just above described.

The remaining portion of iron oxide, iron sulfide and coke removed from the coker comprises the major portion of the stream, from about to about 90% by weight, is introduced into the reducing regenerator which may operate at a temperature of about 1400" F. and 1800" F. In transporting this fraction of solids removed from the coker to the reducing regenerator the solids may be suspended in a hydrocarbon gas or a producer gas and introduced as a iluidized system into the reducing regenerator. Within the reducing regenerator at a temperature of `about 1750 F. liron oxide is actively reduced to elemental iron by the action of hydrocarbon gas which may contain considerable quantities of methane and ethane and may, if desired, comprise desulfurized gas produced as' the lightest product from the coker bubble tower as previously described. The operation of the reducing regenerator is preferably such that the gas produced therein contains carbon monoxide and carbon dioxide in a molar ratio of about 3.0 or more and hydrogen and Water vapor in a ratio of preferably 2.0 or more. A level of uidized solids is maintained within the reducing regenerator from above which gases produced in the production reaction are withdrawn. From below this level is withdrawn a stream of solids comprising nely divided iron.

The gas removed from the upper portion of the reducing regenerator passes through a separator wherein it is freed from suspended solids and the solids-free gas comprises a producer gas containing substantial quantities of carbon monoxide and hydrogen. This gas may be employed as fuel, as a source of hydrogen, or with a moderate amount of purification as a source of a mixture of carbon monoxide and hydrogen which may be employed as a synthesis in a catalytic carbon monoxide hydrogenation conversion for the production of synthetic organic chemicals and liquid fuels. Such catalytic conversions are typied by the I. G.Bergius .process and the Fischer-Tropsch process.

A stream of finely divided iron containing some iron oxides is removed from the lower por- Ytion of the reducing regenerator and a part of to maintain temperature control.

this stream is recirculated with the material introduced into the reducing regenerator in order The remaining portion is cooled such as by passing through a waste heat boiler and is subjected to a magnetic separation or other separation wherein a stream of substantially pure elemental iron particles is recovered. The nonmagnetic material may be returned to the process for retreatment since an appreciable quantity of this may comprise oxides and suldes of iron of relatively lower magnetic susceptibility. The -nely divided iron is introduced at a controlled rate into a mixer to which is also added a controlled quantity of water and at least part of the coker distillate hydrocarbons obtained as products from the coker bubble tower. A slurry of this material is prepared in the mixer in which the ratio of iron to water is such that under conditions in the hydrogenation reactor iron will react with the water to produce a sufiicient quantity of hydrogen to hydrogenate to the desired extent the unsaturated oleiinic and aromatic hydrocarbon constituents present in the coker distillate. This material is removed from the mixer by means of a high pressure pump and passed through a heater capable of quickly increasing the temperature of the slurry to between about 500f F. and 1200o F. depending upon the nature of the coker distillate and the type and severity of hydrogenation desired. Temperatures of the order of 700 F. to 850 F. are suitable for moderate hydrogenation of olenic constituents While temperatures in the upper portion of the range such as from 850 F. to 1100" F. are well adapted to elect cracking in the presence of hydrogen in which case a thermal decomposition of the hydrocarbons in the coker distillate is effected accompanied by immediate hydrogenation of the hydrocarbon fragments formed.

The hydrogenation operation is preferably carried out at superatmospheric pressures which, for example, may be as high as 1000 atmospheres or 15,000 pounds per square inch. Suitable operating pressures for the hydrogenation reaction may run lower than this maximum such as between about 250 pounds per square inch and '7000 pounds per square inch. Under these conditions of pressure and temperature the hydrogenation not only saturates the unsaturated hydrocarbon constituents present, but also decomposes sulfur, nitrogen and oxygen derivatives of hydrocarbons with the formation of hydrogen sulfide, ammonia, and water, respectively. The hydrogen sulfide, at least in part, is found in the hydrogenation reactor eiiluent as iron sulde, While the ammonia formed accumulates in the unreacted water phase. The hydrogenation reactor is preferably provided with means for maintaining a continuous and efhcient agitation of the contents of the vessel in order to insure uniform treatment and to prevent settling of the solids contained in the system.

The hydrogenation reactor effluent comprises a hydrogenated oil phase, unreacted Water and solid particles comprising iron oxide, iron sulfide, and possibly some unreacted elemental iron.. This entire material is introduced into a hydrogenated product bubble tower or other means of separation in which the hydrocarbon phase of the hydrogenator eiuent is fractionated into portions having any desired boiling range. Depending upon the severity of the hydrogenation conditions, a variable quantity of gas containing saturated hydrocarbon gases may be produced. This gas is removed from the bubble tower as droxide. A gas oil productmay be also producedwhich mayhave .a boiling rang'efromabou-t 400 Fl -to 800 The higher boiling hydrocarbon constituents areproduced as a 'hydrogen-ated 'residuum from the lower part of the bubble tower and carries with it iron oxide and iron sulfide formed from the elemental :iron during the hy-f drogenation reaction. This residuum `iis pref-- erabl-y Ytreated to recover :the iron compounds :and may 'be combined with the'heavy vvoil as feed stock to Athe process and returned therewith 4vto the `ook-ing vessel.

'This rnoolidcation ot-.the process, accordi-ng to this :invention permits a substantially complete conversion of 'low `value high density .oils to desirable'hydrocarbon fractions uncontaminated bysul'iur, `having lower 'boiling ranges and suitable for internal combustion engine fuels vor as feed stock in the prepa-ration .of high quality lubricating oils Aand 'lubricating greases. usual hydrogen .compression facilities and lthe expensive sensitive catalyst required `in vsome hydrogenation :processes .fare hereby eliminated;

'in the foregoing 'modiiications ofthe process of this invention it has been found desirable, particularlyzin those cases 'whenlheavy or viscous vhydrogenated residuums 'are formed which .carry suspended solidparticleato .convey Aa diluent oil into .thehydrogenator bubble ltower to assist in conveying this residuum.` Recycling the :Coker bubble residuum as the hydrogenated residuum diluent .has 'been found effective. Generally, the quantity of hydrogenated residuumfis'not large and :not suiiicient to .carry 'the 4amount :of solids present. l

Another-modiiication of the :process tof .this .inyention exists in which a ,substantially :complete yaporization of -the hydrogenated -efuent is eiect-ed to "permit quick separation of the solid particles-from the product. v

A high density7 oilsuch as low A. P. I. gravity crude petroleum is combined-with -a ecker buboie tower residue land witha hydrogenat-ed residuum containing ,a .small Aquantity of iron'oxide particles-and the mixture .is heated to a temperature between about 700' F. .and 1200 F. and intro; duced into the coking reactor. Higher iron .oxide such4 :as .FesOi and FregOs--prod-uced from .iron suliide in theeoxidizing regenerator is .also intradueed .1n-tothe colringreactor 'in which the deposit of -cokeis laid down on the particles.' vliower molecular weight unsaturated hydroearbonarace tions are simultaneously formed. The hydrocarbons thus produced are fractionated in a celrer bubble tower Ywith* the production ofgas, coli-er gasoline, and `coller gas oil. The ecker distillate is employed as -feed stock lto the hydrogenat-ion .unit and includes the gasoline, gas oil, and'fother fractions;

Thecoke-laden iron oxide passes from the coin ing vessel to the reducing regenerator into which vair and part of the gasfproduced from the coke'ibubble tower are introduced. The reducing re generator is v.a vessel in which a iiuid'izedrsus- .pension of solids is lmaintained with the exist# ence .of-a level of soli-ds below' which carbonoxif .da-tion a-m'iV carbonreduction reactions are efe' The fected. A stream of iron .particles1'substantiallyY free of carbon and containing ironwsulflde, ash and sodium chloride in minor amounts, is refmoved. The gas produced from the-upper portion of the reducing regenerator .contains a high concentration of carbonmonoxide and also contains hydrogen and comprises a :suitable pro.v ducer gas which may be used `as fuel or in the conversion of hydrogen sulfide or sulfur dioxide to elemental sulfur in a sui-table reactor.

This stream-oi solid particles removed fromthe reducing kregenerator is divided into-two frac-1 tions, the major proportion of which is combined with the proper quantities of coker -distillateand with water for introductioninto Vthe yhydrogenation step of the process. The minor fraction is subjected to the action or" the magnetic separator by means of which the ash and sodium chloride contents areseparated from the iron compounds.v The ash and salt-free matter obtained in the magnetic separator is combined with the major portion referred to previously and employed in the hydrogenation reaction.

A slurry is `prepared containing Coker distillate, water, and iron in the proper proportions so that the reaction oi iron with water 4will produce a quantity oi hydrogen suflic-ient to efiect the desired -degree of coker distillate hydrogenation. rihis slurry is picked up by a high pressure multistage pump and is passed together with additional Water, if desired, at a 'controlled rate through a heater capable Yof raising the temperature of this linizi-ture to betweenl about 500 F. and about 126051?. For thehydrogenae tion oi a eolcer distillate prepared fromv a low A. P. l. gravity crude petroieum-suchlas that dobtai-ned from the Santa Maria Valley-of California', a hydrogenation temperature-ot about 790- Fito 800 F. is desirableand a pressure oi about I500G to 7060 pounds per `sduareinoh although-pressures as high as about lGGD atmospheres or T5500@ pounds per 'square inch' vmaybe used.

The heated mixture at superatinospheric pressure is passed from theheaterl into a hydrogenation reactor which preferably is provided `with' means for .maintaining the liquid contents thoroughly agitated and the solid particles suspended in the fluid. It is highly desirable to maintain a Ycompletely liquid phasehydrog-,enation With in the hydrogenation vessel under conditions of temperature and pressure given above, water readily reacts with metallic iron withthe evolution of hydrogen and .the formation of iron oxide. The hydrogen reacts with the'colter distillate to be .hydrogenated heioremolecu-lar hydrogen (2- hydrogen Aatoms per molecule) is'v for-med. y"'he freshly formed hydrogen r.isknown as atomic or nascent hydrogen. By consuming the hydrogen immediately and while it Ais in its atomic statey a highly eiioient degree .oi coke-r distillate hydrogenation is eii-ected. It is also possible Athe hydrogenation reactor under temperatures 'aboye 800 F. to eiiect a destructive-hydrogenation in which the boiling range of the hydrogenated product islower than .that of the c oker distillate being hydrogenatedand .the hydrocarbon produced from the reactor may be readily vaporized..

A desulurization reaction also voccurs simultaneously with the hydrogenaton whereby sulfur-containing .hydrocarbon molecules eredecomposed .andthe fragments hydrogenated with ythe formation of hydrogen sulfide and ohydrocarbonsL At least a part` of the hydrogen lsulfide thus formed reacts. *with the {iron orftheiron oxide to form iron suliidewhich is removedwitli the hydrogenated hydrocarbons from the reactor. Oxygen and nitrogen derivatives of hydrocarbons are also decomposed with the formation of water and ammonia, respectively. The water thus formed may react with additional quantities of iron to form hydrogen while the ammonia dissolves in any excess water and may be recovered as an aqueous phase from the hydrogenated material.

The hydrogenated hydrocarbon stream passing from the hydrogenation reactor is suddenly depressured from the superatmospheric operating pressure through one or a plurality of expansion valves to a pressure at or near atmospheric pressure such as from about to 100 pounds per square inch absolute. The material is subsequently passed through a coil in a heater and the combination of the expansion and the heating effects a substantially complete vaporization of the hydrogenated effluent. The gaseous hydrocarbon stream thus produced carries with it suspended particles of iron which may be unreacted and with the iron oxide and iron sulfide. This vapor stream passes into a suitable separator which may comprise a cylindrical tower with a centrifugal separator supported in the upper portion thereof. By means of the separator lthe suspended solid matter is removed and passes over a series of baiiies down through the tower countercurrent to a strippingr gas such as steam which serves to remove remaining traces of liquids or gases from the solids.

The solids are removed from the lower part of the vessel, suspended in a stream of air and conveyed as a suspension into the oxidizing regenerator referred to above in which the oxidation of iron sulfide is effected in a luidized system. The combustion of iron sulfide to form iron oxide results in gases containing considerable quantities of sulfur dioxide. This gas may be chemicallyreduced by reaction with carbon monoxide by combining oxidizing regenerator effluent with the proper proportion of reducing regenerator effluent or producer gas so that the following reaction occurs:

A substantial liberation of heat results which may be employed in a waste heate1` boiler to generate high pressure steam and simultaneously cooling the sulfur-bearing gases to below about 250 F. to permit centrifugal or electrical precipitation of the solid sulfur particles.

Returning now to the hydrogenated effluent separator, a vapor stream comprising vapor phase hydrocarbon and water is removed from the separator and introduced into the hydrogenator bubble tower whereby a fractionation of the hydrogenated effluent is effected. Gases are produced from the upper portion of the tower as well as a hydrogenated and desulfurized gasoline, gas oil and other hydrocarbon fractions of different boiling range. From one tray in the tower an aqueous phase containing ammonium hydroxide may be produced. The hydrogenated hydrocarbon fractions thus produced comprise suitable raw materials for the preparation of high grade internal combustion engine fuels, solvents, lubricating oil and lubricating greases, etc. A small amount of residual material remains in the system and may be produced as a bottoms product from the hydrogenator bubble tower and is returned and combined with the feed stock to the system whereby it is recoked.

The fundamental advantage of this modification lies in the hydrogenation step wherein a substantially complete separation of the unreacted iron if any and the solid iron compounds from the hydrogenated product is effected by expanding the hydrogenator effluent from its superatmospheric pressure to substantially completely vaporize the stream followed by a centrifugal separation of the solid products suspended in the gas. This modification of the operation is readily carried out particularly when the lower boiling products are desirable such as the gasolines and gas oils.

In the modifications of the process of this invention as given above the operating pressures in all cases except that of the hydrogenation are at or near atmospheric pressure. It is preferable to operate a uidized system at pressures somewhat in excess of that of the atmosphere to aid in effecting proper control of the operation. Consequently the preferred pressure range for the operation of the fiuidized coker, the reducing regenerator and the oxidizing regenerator is from about zero pounds to about 100 pounds per square inch gauge, a pressure of about pounds per square inch gauge being well suited to this particular operation. The operation of the coker -bubble tower and the hydrogenated efliuent bubble tower in which hydrogenation distillations are effected are preferably operated at pressures in the same approximate pressure range.

As previously stated, the hydrogenation operation may be carried out at superatmospheric pressures as high as about 1000 atmospheres or about 15,000 pounds per square inch. Operating pressures for the hydrogenation step in the range of from about 3000 to 10,000 pounds per square inch are Well suited to effecting the desired results and operating pressures of from about 4000 to about '7500 pounds per square inch have been found suitable.

In each modification, hydrogen generation arises from the reaction of water with a metal above hydrogen in the electromotive series, that is with a metal capable of displacing hydrogen from water forming a metal oxide reducible by carbon. In the modifications described above iron has been set forth as this metal. There are, however, other metals which are capable of effecting this reaction to the desired extent. Among these metals are zinc, cobalt, nickel, manganese, and the like. This includes the metals of atomic Nos. 25 through 30 of Mendeleefl"s Periodic Table of the elements with the exception of copper.

In the modification of the process of this invention described above, a substantially complete desulfurization of a hydrocarbon fraction may be effected by hydrogenation. This is accomplished in the hydrogenation reactor under the temperature and pressure and other conditions described above. Another modification exists by means of which desulfurization may be at least partially effected in the coking reactor in which at least a part of the elemental iron produced from the reducing regenerator is combined with the hydrocarbon feed stream passing into the coker. The presence of elemental iron at coking temperatures sufficient to thermally decompose sulfur-containing hydrocarbon compounds permits the hydrogen sulfide thus liberated to readily convert part of the iron to iron sulfide. The immediate effect of incorporating elemental iron withthe hydrocarbon stream to the coker is that of reducing the sulfur content of the hydrocarbon @Gif-tige? fractions' produced from the coker bubble tower, and reducing the hydrogen consumption in the hydrogenation step of the combination process.

In the modifications of the process of this invention described above, exclusive reference has been made to the treating of heavy gravity crude petroleums by means of which these hydrocarbons are coked in the presence of iron oxide, the coke-laden iron oxide is suitably treated to reduce the iron oxide to iron, and the iron is reacted with water in thepresence or at least part of the hydrocarbon products obtained during the coking reaction to form hydrogenated and desulf-urized liquid and hydrocarbon fractions. It should not be understood that the process or this invention is exclusively applicable to the treating of petroleum hydrocarbons since similar desirable results may be'y brought about in employing the heavy gravity oils` and tars obtained from coal distillation as feed stock. These tars and oils are essentially aromatic in nature containing high molecular Weight condensed ring structures and include such materials as benzene, toluene, xylene, naphthalene, anthracene,` phenanthrene, chrysene, picene, and-otherpolynuclear aromatic aswell as heterocyclic compounds. Various cond densed structures such as indene and fluorene,v as well as the higher mo-lecular weight aromatic acids known as phenols and the higher molecular weight aromatic bases of thel pyridine type also occur. By employing such coal tar fractions as feed stock in the'process of this invention, desirably lower boiling hydrocarbon fractions may be obtained which may contain a variable quantity of residual aromatic hydrocarbons and mayk also contain variableI quantities of cyclic saturated hydrocarbons of the naphthene type as well as paraflinic` hydrocarbons depending upon the se- Verity of the coking and of the' hydrogenation step. Highly desirableL hydrocarbon fractions may be readily obtained from this typefof feed stock. p

The process, according tothis invention may be further applied to thel hydrogenation or' nor"- mally solid carbonaceous materials of which examples are bituminous coal,v lignite', peat,v brown coal, and the like. The process of this invention is modied to theextent that the carbonaceous material or coal to betreated is finely pulverized in a suitable grinding mill and mixed With a tar recycle to formv a paste or a liquid suspension" of coal solids in the oil. Thista'r recycle maybe one obtained from the coker wherein the-paste iscoked with the liberation of further quantities of aromatic` typeY coal tars or it may be a residual oil from the hydrogenation eluent bubble tower which desirably isreprocessed. During thefoper'- ation of this modification of the process iron oxide produced from the oxidizing regenerator is combined With the paste andintroduced' into the Coker or it may' be introduced into the coker directly. The hydrocarbon oilsV liberated from the coal during coking are subsequently mixed with iron, for example, and. Water and hydrogenated under high pressure as previously' desc'ribed. Such materials as oil sand, tar' sand, oil-soaked diatomite may be treated in a manner similar to thatdescribed above for handling c'a'rbonaceous sclidssuch as coal'. y

The process of lthe presentinvention described in' detail above permits the ready conversion of carbonaceous materials' whether they are solids -or liquids to desirablehydrocarbon fractions substantially free of contaminating vele'irientsby a combined operation of colzing in the presence .ofy a metal oxide, depositing a carbonaceous solid on the metal oxide, and hydrogenating the therinz'ilY Way of illustration. It should be understood that various other modications and adaptations thereof may be made by those skilled in this particular art Without departingfrom the spirit and scope of this invention as set forth in the' appended claims.

We claim:

1. A process which comprises pyrol'yzingfa iiydrocarbon oil in the presence of spent solid'particles to form a hydrocarbon pyrolysis product and coke-laden particles, said spent particles' being formed by reacting regenerated particles with water to liberate hydrogen therefrom, reacting said coke with saidy spent particles to' forni riee generated particles in the presence of oxygen` containing gas, combining at least a portion of saidl regenerated particles with at least-a portion of said pyrolysis product, subjecting the mixture thus formed to hydrogenating conditions ofpres'-r sure and temperature in the presence of Water in the liquid phase thereby hydrogenatingv said pyrolysis product and forming said spent 'solid particles, separating hydrogenated oils from said spent particles and recirculating said particles;

2. A process which comprises coking a hydro-'- carbon oil in the presence of iluidized particles of an oxide of a metal above hydrogen in the electromotive series to form coke-laden metal oxide particles and a Coker` distillate, said metal oxide being in a higher oxidation state, separating coke-laden particles from said ecker distillate, heating said coke-laden iron oxide particles to remove coke and regenerate the. metal .oxide particles to a lower oxidation state, reacting the regenerated lo-Wer metal oxide particles Ywitl'i Water in the presence of at least av portion of said-Coker distillate thereby hydrogenating. said distillate and forming said metal oxide of higher Y oxidation state, separating this higher metal oxide from the hydrogenated product andrecirculating said higher metal oxide. A

y 3. A process according4 to claim 2 wherein said hydrocarbon contains suspended` carbonaceous solids. Q

4. A process accordingto claim 2` whereinfs'a'id hydrogenated product is fractionatedv leavingl al hydrogenated residuum, suspending nely divided solid carbonaceous solids therein and recirculating the mixture thus formed' tohydr'ogenate 'said solid carbonaceous solids.

` 5. A process according to claim 4 wherein said finely divided carbonac'eous'solids are particles' of coal.

6. A process' Which comprises cokinga hydrocarbon oil in the presence' of fluidiz'ed particles of a higher oxide of iron to form coke-ladenl higher iron oxide particles and a Coker distillate,v separating said particles' from said distillate, fluidiaing said coke-laden higher iron oxide particles at a temperature sufficient to cause reactionbetween the higher oxide and the coke thereby forming coke-freereduced particles containing iron in a lower oxidation state capable of reacting with waterto liberate hydrogen, contacting at least a. portion of said coker distillate with said coke-free reduced particles thus formed in the presence of water in the liquid phase thereby hydrogenating said coker distillate to form said higher iron oxide and a hydrogenated product, distilling said hydrogenated product to recover hydrogenated hydrocarbon fractions therefrom leaving a hydrogenated residuum containing particles of said higher iron oxide and combining said hydrogenatecl residuum with said hydrocarbon oil to be coked.

` 7. A process according to claim 6 wherein said higher iron oxide particles are reduced with coke to ferrous oxide (FeG).

'l 8. A process according 'to claim 5 wherein said higher iron oxide particles are reduced with coke to iron.

` 9. A process which comprises coking a hydrocarbon oil contaminated with sulfur compounds in the presence of fluidized particles of ferrie oxide to form a coker distillate contaminated with sulfur compounds and coke-laden ferrie oxide particles, separating said particles from said distillate, fiuidizing coke-laden particles of ferrie oxide at an elevated temperature to effect reduction of the ferric oxide to elemental iron, separating iron particles thus formed, contacting at least a portion of said coker distillate with said elemental iron particles in the presence of Water in the liquid phase whereby said coker distillate is hydrogenated and desulfurized by hydrogen formed through the interaction of Water and said iron forming a desulfurized hydrogenated product, iron sulfide, and ferric oxide, distilling said hydrogenated product to recover desulfurized hydrocarbon fractions, separating particles of iron sulfide formed in desulfurizing said coker distillate, fluidizing said particles of iron sulfide in an oxygencontaining gas thereby forming ferric oxide and sulfur dioxide and recirculating the ferric oxide thus formed.

" lOl A process which comprises coking a hydrocarbon oil contaminated with hydrocarbon compounds of sulfur in the presence of fluidized particles of ferric oxide to form a sulfur compound contaminated coker distillate and ferric oxide particles laden with coke, separating said particles from said distillate, fiuidizing said coke-laden ferrie oxide particles in contact with an oxygencontaining gas at an elevated temperature to form carbon monoxide and particles of elemental iron, separating iron particles thus formed, reacting said particles of iron with Water in the presence of at least a portion of said coker distillate in the liquid phase thereby hydrogenating 'and .desulfurizing said coker distillate forming iron sulfide and ferrie oxide, distilling the hydrogenation product to recover a desulfurized hydrocarbon fraction therefrom, recovering particles of iron sulfide, fluidizing said iron sulfide in ran oxygen-containing gas thereby oxidizing said iron sulfide forming sulfur dioxide and ferric oxide, separating said ferrie oxide particles, re-

cycling said ferric oxide, combining at least a portion of the carbon monoxide produced in reducing said ferrie oxide with at least a portion of the sulfur dioxide bearing gases produced by iron sulfide oxidation, and effecting an elevated temperature reaction of said carbon monoxide with vsaid sulfur dioxide to produce elemental sulfur.

11. A process according to claim 10 wherein the efiiuent gases from the reaction involving carbon monoxide and sulfur dioxide are cooled to a temperature above about 225 F. to separate sulfur in liquid form.

12. A process according to claim 10 wherein the effluent gases from the reaction involving carbon monoxide and sulfur dioxide are cooled to a temperature below about 250 F. to separate finely divided particles of sulfur in solid form.

13. A process according to claim 10 which comprises contacting the residual gases from the carbon monoxide reaction with sulfur dioxide which contain unreacted quantities of sulfur dioxide and hydrogen sulfide with the reduced particles produced by elevated temperature reaction of said coke-laden ferrie oxide to form further quantities of iron sulfide and the like. and recirculating said iron sulfide to the process to effect a substantially complete recovery of the hydrocarbon compound of sulfur as elemental sulfur.

14. A process according to claim 10 including the step of combining ferrie oxide produced in the oxidation of iron sulfide With said hydrocarbon oil to be coked to form further quantities of iron sulfide.

15. A process according to claim 10 including the step of magnetically separating particles of iron sulfide from said hydrogenation product.

16. A process which comprises coking a hydrocarbon oil in the presence of iiuidized particles of Fe304 to form a coker distillate and coke-laden FesO4 particles, fiuidizing said coke-laden Fez04 particles in heated gases thereby forming carbon monoxide and reduced iron oxide particles in a lower state of oxidation, separating said reduced particles from said carbon monoxide gases, reacting said reduced particles with Water in the liquid phase under superatmospheric pressure in the presence of at least a portion of said coker distillate to hydrogenate olefinic constituents thereof while reforming said Fe3O4 and desulfurizing said distillate forming iron sulfide, fractionating the hydrogenated product to obtain a hydrogenatedA residuum containing FeaOi and iron sulfide, combining said hydrogenated residuum with said hydrocarbon oil to be coked, magnetically separating iron sulfide from circulating solids streams in the process, fluidizing said iron sulfide in an oxygen-containing gas thereby forming sulfur dioxide and particles of FezOi at an elevated temperature, contacting said particles of FezOs with at least a portion of said carbon monoxide gases produced in the FesO/x reduction thereby reducing said particles of FezOa to Fe304 and recirculating the particles of Fe3O4 thus formed.

1'7. A process Which comprises establishing a fluidized coking zone, a fluidized reducing regenerating zone, a fluidized oxidizing regenerating zone and a liquid-phase hydrogenating and desulfurizing zone, combining a hydrocarbon oil contaminated with sulfur compounds with a coker distillate residuum and a hydrogenated residuum containing suspended particlesof solid iron compounds such as iron oxides and iron sulfide, heating the combined hydrocarbon oil and residuum stream, contacting the heated stream with heated particles of Fe3O4 prior to introducing the mixture thus formed into said fluidized coking zone to form coke-laden Fe3O4 particles and a coker distillate, separating coke-laden particles of Fe304 from said coker distillate, distilling said coker distillate to produce said coker distillatev residuurri "and selected'l hydrocarbon fractions of said coker distillate, introducing the separated particles of4 FecOLi intosaid iiuidized reducingregenerating zone whereinsaid FesO4 is reduced to an iron compound in a lowerv oxidation vstate forming a gas containing carbon monoxide, magnetically separating the reduced iron compound from relatively less magnetic solids such as iron sulde removed from the reducing regenerator, combining the reduced iron compound thus-recovered with at least a portion of said coker distillate, reacting said iron compound with water in said hydrogenating zone at an elevated temperature in the liquid phase thereby hydrogenating said coker distillate and simultaneously effecting a coker` distillate desulfurization forming iron sulfide, distilling the hydrogena'ted product thus formed to separate desirable sulfur-free hydrocarbon fractions thereof leaving a hydrogenated residuum containing Fe'aOi and iron sulfide, recirculating said hydrogenated residuum to saidfiuidized coking zone, oxidizing said iron sulfide magnetically separated from'said reducing regenerating zone in said fluidized oxie dizing regeneration zone to form ferric oxide and a gas containing sulfur dioxide and recirculating the FeaOi thus formed to said luidized reducing regeneration zone.

18. A process according to claim 17 wherein at least a portion of the solids withdrawn from said uldized reducing regeneration zone are introduced with the combined hydrocarbon streams to said fluidiz'ed coking Zone wherein at least a portion of the sulfur compounds are decomposed to form iron` sulfide".

19. A process according to claim 1'? wherein hydrocarbon compounds of nitrogen are present in said hydrocarbon oil and are hydrogenated in said liquid phase hydrogenationzone in the pres'- ence of water to form ammonia, said ammonia being recovered as ammonium hydroxide upon distillation of the hydrogenated product from said hydrogenated zone.

20. A process according to claim 17 wherein said coker' distillateis'introduoed into a distillation zone to' producean overhead-gas stream containing normally gaseous hydrocarbons, contacting said gas thus'produced with anl absorber oil to remove normally'liquid hydrocarbon com- 'pounds leaving a dry gas, desulfurizing said dry gas to remove hydrogen sulfide, and introducing thedesulfurized dry gas thus formed directly into said uidized reducing regeneration zone.V

21. A process according i u the steps oi dividing the reduced particles removed irom said reducing regenerating zone into `a major portion anda minor portion, introducing said major portion with said cokerl distillate directly into said hydrogenating and desulfurizing zones, subjecting the minor portion to magnetic separation of iron sulfide therefrom, introducing the thus separated iron sulfide into said oxidizing regenerating zone, and passing the remaining part of said minor portion to said hydrogenating and desulfurizing zone.

22. A process according to claim 17 wherein catalytic quantities of a hydrogenation catalyst are circulated with the str eam of iron compound particles. y

23. A process which comprises establishing a fluidized coking zone, a fiuidized reducing regeneration zone, a fluidized oxidizing regeneration zone and a liquid phase hydrogenation zone, combining a hydrocarbon oil containing hydrocarbon compounds oi sulfur and nitrogen with a correr distillate vresiduurn and'` a Bydrogeriated product residuuin containingl suspended solid particles ofFesOfr and' Fes, heating the combinedy fiuidized reducing regeneration' zone wherein a Fego'i reduction is effected at a temperature of from about 1400 F. to about 1800ov F. to forni coke-free particles containing iron in loweroxidation states and a gas containing carbon mon@ oxide, removing the reduced particles thus formed from said reducing regeneration zone; separating FeS from said particles containing iron in a lower oxidation state, fl'uidizingv said Fes in an oxygen-containing gas in said oxidizing regeneration zone at a temperature between 1000" F. and about 2000 F. to form a gas containing sulfur dioxide and particles; of FesOii, recirculating said FeaOi to said reducing regeneration zone, combining a portion or carbon monoxide gases from said reducing regenerationzor'ie with aportion of sulfur dioxide gases from said oxidizing regeneration zone in al controlled ratio to form to claim 17 includingvv elemental sulfur combining at least aportion of saidv colrerv distillate with said Vreduced particles containing iron in lower oxidation states, reacting said particles with'water at a temperature of from 500" F. to about 1200" F; ata pressure upto about 15,00'0'pounds perl square inch tohy'drogenate and desuliurize said coker' distillatethereby forming FeS from said hydrocarbonl compounds oi sulfur and ammonia. from saidv hydrocarbon compounds of nitrogen, distilling the hydrogenated product" to` recover des'ulfurize'd hydrogenated hydrocarbon v'fractions'.A thereof leaving a hydrogenated residuum-'containing Fes and Fe3O4, and recirculating said hydrogenatd residuum.4 with said hydrocarbon oil and said coker distillate resid'uumto said'fluidi'zed coking zone.

24. A process according to claim '23' wherein Asaid reduced particles' containing iron in -alower oxidation state removed from' said reducing rej-A generation zone comprise? particles# of ferrous oxide (FeO) formed in said reducing `regeneration zone while maintaining a circulatinggas stream in said reducing regeneration zone-.having a carbon monoxide to carbon dioxide ratio of between 0.5 to 3.0 and while introducing a stream of `hydrocarbon gas into said reducing regenerar tion zone.

25. A process according 'to claim 23 wherein said reduced particles removed fromsaid reduclng regeneration zone comprise elemental iron produced in said reducing regeneration zone while maintaining therethrough a recirculating gas stream containing a carbon monoxide to carbon dioxide ratio of from about 2.5 to 5.0 and while introducing a stream of hydrocarbon gasv into said reducing regeneration zone.

26. A process according to claim 23 wherein the particles of iron compound removed from said nuidized oxidizing regeneration zone comprise FezOa and which is reduced to Fe304 by countercurrent contact with a part of the carbon 31 monoxide bearing gases at a temperature between 1400 F. and 1800 F. removed from said uidized reducing regeneration zone and said Fe3O4 is subsequently recirculated. Y

27. A process according to claimA 23 wherein said liquid phase hydrogenation zone is provided With a continuously recirculating stream of hydrogenated effluent containing suspended particles which is combined with said coker distillate containing particles of iron compound in its lower state of oxidation and is recirculated in sufficient quantities through a heating zone and subsequently through said liquid phase hydrogenation zone in the presence of water to efect a substantially instantaneous heating of said Coker distillate and iron to temperatures between about 500 F. and 1200 F. required to effect hydrogenation and desulfurization.

28. A process according to claim 23 wherein said Huid to be hydrogenated comprises from about to about 35% by weight of a wateroxidizable compound of iron such as iron and ferrous oxide (FeO) from about 2% to about 25% by weight of water and from about to about 90% by weight of coker distillate, to which iiuid has been added a small quantity of a hydrogenation accelerator selected from the group consisting of Water-soluble halides of calcium, magnesium, iron, manganese and ammonium.

29. A process according to claim 23 which comprises combining said coker distillate with particles of an iron compound capable of reacting with water to liberate hydrogen to form a slurry, passing said slurry through a heating zone into said hydrogenation zone, separately heating Water under superatmospheric pressure, introducing the heated water into said hydrogenation zone so that the hydrogenation reaction takes place completely within the hydrogenation zone.

30. A process according to claim 23 wherein the residual gases remain after the separation of elemental sulfur produced in the sulfur dioxidecarbon monoxide reaction contains unreacted sulfur dioxide which is recovered by the step oi contacting such residual gases with the coke-free particles removed from the reducing regeneration zone.

31. A process according to claim 23 wherein said hydrogenated product is flash vaporized by reducing the pressure thereby separating the hydrogenated product into a vapor and a hydrogenated residuum containing iron sulde and a higher iron oxide, distilling the vapor thus formed,v and recirculating the hydrogenated residuum.

32. A process according to claim 31 wherein said hydrogenated product is substantially cornpletely vaporized forming a Vapor containing suspended solid particles, the steps of separating said solid particles from said vapor and recirculating the thus separated solids to said oxidizing regenerating zone.

33. A` process which comprises thermally pyrolyzing a hydrocarbon oil in the presence of particles of a higher oxide of iron and ironsuliide to form a coker distillate and coke-laden particles in a iiuidized coking zone, separating said coke-laden particles from said coking zone, introducing between and 90% by weight of the solids stream thus removed to a fluidized reducing regeneration zone in which the higher oxides of iron are reduced While maintaining a continuous gas recycle stream containing carbon monoxide through said reducing regeneration zone to form reduced particles, introducing between about 10% and about 50% of the solids stream to a fluidized oxidizing regenerator wherein said iron sulfide is oxidized to form further quantities of higher iron oxide, recirculating the higher iron oxide thus. formed to said fluidized coking zone, combining said reduced particles separated from said luidized reducing regenerator with at least a portion of said Coker distillate, reacting said reduced iron compound particles in the presence of water at a temperature of about 750 F. and at a pressure as high as 15,000 pounds per square inch in the liquid phase to desulfurize and hydrogenate said coker distillate to form a hydrogenated product, and said higher iron oxide and iron sulfide, distilling said hydrogenated product to form desuliurized fractions thereof leaving a hydrogenated residuum containing said higher iron oxide and iron sulfide, and recirculating the residuum thus formed to said iluidized coking zone.

HOMER C. REED.

CLYDE H. O. BERG.

CHARLES B. LEFFERT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS OTHER REFERENCES Kalbach Improving Solids-Gas Contacting by Fluidization, Chem. and Met. Eng. June 1944, pages 94-98. f

Kite et al., Fluidization in Non-Catalytic Operations, Chem. and Met. Eng., vol 54 No. 12, 1947, pages 112 to 115. 

1. A PROCESS WHICH COMPRISES PYROLYZING A HYDROCARBON OIL IN THE PRESENCE OF SPENT SOLID PARTICLES TO FORM A HYDROCARBON PYROLYSIS PRODUCT AND COKE-LADEN PARTICLES, SAID SPENT PARTICLES BEING FORMED BY REACTING REGENERATED PARTICLES WITH WATER TO LIBERATE HYDROGEN THEREFROM, REACTING SAID COKE WITH SAID SPENT PARTICLES TO FORM REGENERATED PARTICLES IN THE PRESENCE OF OXYGENCONTAINING GAS, COMBINING AT LEAST A PORTION OF SAID REGENERATED PARTICLES WITH AT LEAST A PORTION OF SAID PYROLYSIS PRODUCT, SUBJECTING THE MIXTURE THUS FORMED TO HYDROGENATING CONDITIONS OF PRESSURE AND TEMPERATURE IN THE PRESENCE OF WATER IN THE LIQUID PHASE THEREBY HYDROGENATING SAID PYROLYSIS PRODUCT AND FORMING SAID SPENT SOLID PARTICLES, SEPARATING HYDROGENATED OILS FROM SAID SPENT PARTICLES AND RECIRCULATING SAID PARTICLES. 